2. Find a hobby.

Whether it's knitting or an improv class, find something you do purely for pleasure and personal fulfillment.

"Pursue it on [a] regular basis. It will give you tremendous benefits in the future," writes Deepak Rana.

Those benefits may include social support, if your hobby is something like team sports, and relief from daily stressors, so that you don't burn out in your job.

3. Appreciate your family and close friends.

In your 20s, you might be working hard to launch a successful career and find a romantic partner. With all that's going on, it's easy to forget the people who helped get you to where you are today.

But several Quora users mention the importance of staying in touch with family and friends.

"Talk to your parents, your grandparents, relatives, your friends," writes an anonymous user. "While you are in your 20s, your parents are aging very quickly, your grandparents are getting very old, some day you will not be able to talk to them any more, and your old friends will grow apart from you."

4. Save money.

It might seem hard to sock away a chunk of cash for retirement when you aren't earning as much as you'd like. But the magic of compound interest means that if you save $100 a month in your 20s, it will add up to significantly more than if you save $100 a month in your 40s.

Plenty of people wish they'd acted on this knowledge in their youth: "As a middle-aged woman looking back to my 20s, this is the one thing I regret not doing most," says Shao Wang.

5. Visit a foreign country.

Before you get married, have kids, and become enmeshed in your career, take the time to see a part of the world you've never seen before.

Once you're there, consider ditching the hotel and guided tour and striking out on your own.

"During [your] travels, you learn more than you will glean from any book. Don't be a tourist, travel like a traveler. Meet a lot of people in your travels. Interact with them," Rana says.

7. Develop healthy habits.

Your health is arguably the most important asset you have in life.

That's why Thaís Freitas advises: "Take very good care of your body and your health. Practice sports, work out, eat healthy. That's the only thing that is really important to do before your 30s, and that will allow you to be free, able, and happy in any age."

8. Do something you don't think you'd enjoy.

"Do an activity you've decided you don't like, even though you've never done it — watch a foreign film, or go see an opera, or get a massage, or go to a meditation session ... we all have biases that need vetting," says Milo Grika.

You could discover that your tastes have evolved and you're now an absolute opera fiend (or meditation guru, or foreign film lover, etc.). Worse comes to worst, you'll find you still hate the activity and won't have to do it again.

9. Learn to cook.

Besides being able to impress friends and family with your new-found culinary prowess, research suggests home-cooked meals are more nutritious than restaurant fare.

10. Travel alone.

It's a good idea to travel abroad in your 20s. It's an even better idea to do it solo. Multiple Quora users recommended that people go on a trip alone in their 20s.

"This teaches you how to survive even if you are left alone," says Sudarshan Thirumalachar.

"Survival" could mean learning how to fend for yourself, but it might also mean knowing how to occupy and entertain yourself without depending on other people to make you happy.

11. Figure out your definition of success.

Maybe you're hoping to launch a killer startup, or maybe you'd like to write bestselling novels. While you're still in the early stages of your career, it's important to figure out what success means to you personally.

Writes Stefan Tasevski, "You should start thriving and [seeing] your meaning of 'success' and how you will eventually get to it."